This invention relates generally to turbine engine structures and more particularly to materials and designs for improving anti-icing characteristics from such structures.
One common type of aircraft powerplant is a turbofan engine, which includes a turbomachinery core having a high pressure compressor, combustor, and high pressure turbine in serial flow relationship. The core is operable in a known manner to generate a flow of propulsive gas. A low pressure turbine driven by the core exhaust gases drives a fan through a shaft to generate a propulsive bypass flow. The low pressure turbine also drives a low pressure compressor or “booster” which supercharges the inlet flow to the high pressure compressor.
Certain flight conditions allow for ice build up on the leading edge structures, and in particular, the fan and booster flowpath areas of the engine. One specific leading edge structure of interest is the engine's booster splitter. The splitter is an annular ring with an airfoil leading edge that is positioned immediately aft of the fan blades. Its function is to separate the airflow for combustion (via the booster) from the bypass airflow.
It is desired to minimize ice build up and shed volume from the splitter during an icing event. This in turn minimizes risk of compressor stall and compressor mechanical damage from the ingested ice.
It is known to heat engine structures for anti-icing. However, because the splitter is exposed to fan by-pass air, injection of hot air directly into the splitter would lead to insufficient heating at the nose due to heat loss to the fan air.
Accordingly, there is a need for a splitter which is efficiently heated so as to be resistant to ice buildup.